Maps

I actually thought about this myself not long ago. I've had my 920 for about 2 months and have not had to do an update to the maps yet after updating them the day I got the phone. This is a guess here, but I'm going to say 3-4 times a year. My Garmin Nuvi which I use in the car has free lifetime maps. Garmin use Navteq (Nokia) for their maps. This gets 4 map updates per year (so a new map every 3 months). Whether the phones get the same cycle of updates per year, like I said I'm not sure, but I would say it would be similar.

I do believe the HERE maps now have incremental updates as well, so you don't download a whole map when updating. The updates will just add/remove roads, so the updates will be a much smaller size to download.